Fernández Espejo, E., L. Stinus, U. Spampinato, P. De Deurwaerdère, S. Caillé, and G. F. Koob. “ But Its Inhibition by Stimulation 5-HT1A Receptor Increases the Effectiveness of the Clonidine in Rats / El Sistema endógeno De Serotonina No Participa En La Abstinencia opiácea. ”. Health and Addictions Journal/Revista Salud Y Drogas, vol. 3, no. 1, June 2003, doi:10.21134/haaj.v3i1.150.